Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds genuinely new behavioral context on data granularity ('city or park level only') and freshness ('dated snapshots, not live quotes'). These are practical caveats an agent cannot infer from structured fields, though pagination/output behavior is left untouched.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The Purpose/Guidelines/Limits structure is front-loaded and each section earns its place. The trailing 'Ex: query_green_power()' is a wasted line since it demonstrates no arguments and teaches the agent nothing.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, a fully documented parameter set, and rich annotations, the description only needs to supply scope and caveats, which it does. It could be stronger by clarifying how this differs from price/comparison siblings, but nothing critical for correct invocation is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% with 5 documented optional parameters, so the schema already carries all parameter meaning (limit, offset, keyword, language, response_format). The description adds no syntax or filtering guidance beyond that, making the baseline 3 appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific resource (green power trading and direct-connection projects) and enumerates its contents: certificate prices graded by production year, traded volumes, and flagship projects. That is concrete enough for an agent to know what comes back, though it never distinguishes itself from related siblings like compare_carbon_prices or get_power_consumption_stats.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives an explicit when-to-use directive ('use for green-power price and project questions'), which is clear context rather than mere implication. It stops short of naming alternatives or exclusions, so it does not reach the when/when-not/alternatives bar of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.